This invention relates to a safety device for a laundry washing machine or the like which has a treatment chamber with an inlet opening for laundry that is pressurized in order to treat the laundry with a treating agent, for instance, carbon dioxide. During treatment, the inlet opening of the chamber is covered by a door that is secured to a housing surrounding the chamber by a locking device.
Washing machines of the type described above are previously known and have been developed because of environmental reasons in order to replace chemical washing methods where, for instance, trichloroethylene or perchloroethylene are used. When these alternative machines use, for instance, liquid carbon dioxide, however, there is a complication with respect to the technique being used since the treatment chamber has to be under pressure during the treatment procedure. Machines of this type are described in, for instance, U.S. Pat. No. 5,267,455. Thus, it is necessary to prevent the door from being opened when the treatment chamber is pressurized since an unintentional opening of the door in this state could cause personal injuries as well as damages on property.
This invention provides a simple device by which the washing machine door is locked and is prevented from being opened as long as the pressure prevails in the treatment chamber, even if for any reason the locking mechanism would not work properly, for instance, because of malfunctions in the system controlling the opening and closing of the door.
This is achieved by an apparatus having a locking means that has a first holder device which secures a door to a housing surrounding the chamber and a second holder device which is activated if the first holder device is deactivated, thereby keeping the door in its closed position as long as the chamber is pressurized.